The present invention relates to a coupling device, particularly for a piston rod type damper.
In the case when switching a comparatively heavy movable body to rotate between an open position and a closed position, by interposing a piston rod type (for example, constituted such that a piston rod is slid against a cylinder as in an air damper) damper between the main body and the movable body, it is handled such that the movable body is not rotated suddenly toward the direction of the open position by unlocking of the rod means.
FIG. 8 shows the structure disclosed in Patent Document 1 as one example thereof. In FIG. 8, symbol 50 is an instrument panel as a main body, symbol 55 is a glove compartment as a movable body, and symbol 60 is an air damper which has a cylinder 61 and a piston rod 62. Here, the glove compartment 55 is supported to be capable of being switched to rotate between an open position and a closed position on a corresponding placement part of the instrument panel 50, and also it is locked in the closed position by a locking means not illustrated. The air damper 60 is coupled with the cylinder 61 which is attached to the instrument panel 50 and the piston rod 62 which is attached to the glove compartment 55, respectively to be capable of rotation. In this structure, it is made possible to attach or couple without using a screw or shaft member as required in the past. That is, the cylinder 61 has a contracted diameter part 61a which is provided on the front end side and shaft parts 63 which are provided on both sides of the contracted diameter part 61a. Also, the cylinder 61 is coupled to be capable of rotation, in a state having the contracted diameter part 61a placed between sides of a raised wall 51 which are provided on the instrument panel 50, by having the shaft parts 63 on both sides fitted into bearing hole parts 51a on the sides of the corresponding raised parts.
As opposed to this, the piston rod 62 has a fitting hole 64 which is provided on the projecting end. Also, the piston rod 62 is coupled to be capable of rotation by being inserted through the outside part of the glove compartment 55 from between sides of the raised wall 51, and fitting together the fitting hole 64 on the projecting end and a fitting projection 56 which is placed to project on the outside surface of the glove compartment 55.
Patent Document 1: Japanese Unexamined Patent Publication No. 2002-106245
Although a coupling structure as mentioned above is simple, it has problems from viewpoints such as the following.
(a) This kind of damper also may be placed inside the glove compartment due to vehicle body design. By such specification, the structure in FIG. 8 cannot be adopted, and in addition, if it is coupled by being attached using a screw or shaft member as in the past, the external appearance is degraded and the attractiveness is difficult to maintain.
(b) It is preferable that this kind of damper be jointly usable for various purposes, and from that viewpoint, instead of the contracted diameter part and the shaft parts of the cylinder as in FIG. 8, one would like to make them as shaft holes to be commonly used as coupling parts for both the cylinder and the piston rod, so that they can be coupled easily and quickly using those shaft holes.
(c) The piston rod is coupled to the glove compartment by fitting together the fitting hole and the fitting projection. However, in this structure, because the glove compartment is comparatively large and some extent of play is set in the part of placement on the instrument panel side, for example, if the glove compartment is subject to a great load in the lateral direction, there is a risk that the fitting projection may come out from the fitting hole. Also, the cylinder is supported by being coupled to the instrument panel by fitting together the shaft parts and the bearing hole parts. However, in this structure, when the cylinder is subject to a load in the left-right direction in FIG. 8 by means of the piston rod, there is a risk that the raised walls may be displaced and the shaft parts may come out from the bearing hole parts. One would like to eliminate the above instability factor.
The purpose of the present invention is to eliminate problems such as those described above with structural simplicity, and to provide a coupling device having excellent coupling operability and external appearance characteristics during use, and moreover, it does not come off unexpectedly, while maintaining a simple shaft hole structure as a damper side coupling part.
Further objects and advantages of the invention will be apparent from the following description of the invention.